<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .wrap{
            width: 300px;
            height: 300px;
            background: pink;
        }
        .bg{
            background: gray !important;
        }
        .round{
            border-radius:50% ;
        }
    </style>
</head>
<body>
    <div id="app">
        <!--class: 非vue指令-->
        <!--<div v-bind:class="className"></div>-->
        <div :class="{wrap:true}" :damu="msg"></div>
    </div>
</body>
<script src="./js/vue.js"></script>
<script>
    Vue.config.productionTip = false

    new Vue({
        el:"#app",
        data:{
            msg:"达姆"
        }
    })
</script>
</html>